This invention relates to reusable and re-collapsible containers, and particularly to a one-piece container construction having a peripheral side wall which is arranged to include at least three sections of differential wall thickness and diameter to thereby permit movement of the container from an extended to a collapsed position by reason of a telescoping relationship between the various sections of the peripheral side wall.
Collapsible containers, drinking cups and the like are, of course, well known. For example, in applicant's own prior U.S. Pat. No. 4,930,644, a collapsible, thin film plastic container is disclosed wherein a major portion of the container side wall has a reduced wall thickness to permit random collapse of the side wall. In U.S. Pat. No. 4,865,211, a plastic bottle having a uniform wall thickness throughout the side wall, is configured to permit collapsing of the container through telescoping movement of one portion of the side wall into another portion of the side wall.
In U.S. Pat. No. 4,875,576, a container is disclosed wherein an intermediate portion of the side wall incorporates a bellows-type arrangement for facilitating collapse and extension of the container. The patent also discloses the use of helical creases which spiral or angle between first and second portions of the container side wall to facilitate collapsing action of the creased portion of the side wall.
In U.S. Pat. No. 4,873,100, a bi-stable, expandable plastic bottle is disclosed which incorporates a bellowstype side wall for movement between collapsed and extended positions.
In U.S. Pat. No. 2,880,902, a collapsible, drinking cup (or camera bellows) is disclosed wherein the side wall is composed of alternating thick and thin portions.
The present invention incorporates a number of features not previously found in the prior art and which result in simple, easy-to-use, low cost containers which may be used and reused by the consumer as desired, and which may be stored in a collapsed condition, maximizing storage space, etc. At the same time, by significantly reducing the thickness of the container side wall in an intermediate portion thereof, source reductions in the amount of plastic required to manufacture the containers are realized.
More specifically, the invention provides in each of the variously disclosed embodiments, a one-piece, extruded and blow molded container formed with a peripheral side wall divided into upper, intermediate and lower portions, with the upper and lower portions having significantly greater wall thicknesses than the intermediate portion. For example, it was originally determined that the intermediate portion may have a wall thickness of between about 2 and about 12 mil, and preferably about 8 mil, which permits the intermediate portion to reverse fold as the upper and lower portions, which may each have a wall thickness in the range of about 25-60 mil and preferably about 45 mil, are moved toward one another in the aforementioned telescoping relationship.
It has now been determined that the wall thickness of the intermediate side wall portion can fall in the range of about 2 to about 20 mils, and that the wall thickness of both the upper and lower side wall portion can fall in the range of 25-75 mils or more. It will be recognized in any event that the thicknesses in each wall section will vary somewhat (circumferentially as well as axially) as a result of the plastic forming process, and the thicknesses here are to be regarded as average thicknesses within the specifically identified portions of the container.
It is also a feature of the invention that the peripheral side wall include surface configurations which facilitate the axial collapse and extension of the container. Thus, in each of the disclosed embodiments, the intermediate peripheral side wall portion is formed with an inwardly and downwardly tapered profile, i.e., a decreasing diameter in the downward direction; and the lower peripheral side wall portion is formed with a downwardly and outwardly tapered profile, i.e., an increasing diameter in the downward direction. In addition, at the interface between the three sections, the changes in wall thickness provide a pair of annular steps which, in effect, provide a crease to facilitate the folding or collapsing action. The collapsing action is also facilitated by reason of the fact that the maximum and minimum diameters of the tapered intermediate side wall portion create a radial clearance between the lower edge of the upper side wall portion and the upper edge of the lower side wall portion, so that there is minimal frictional engagement between the upper, intermediate and lower side wall portions during collapsing and extending. It has also now been determined that, as a practical matter, the radial clearance which permits the intermediate portion to reverse fold with minimal sliding friction can be determined as a function of the wall thickness of the upper side wall portion, as explained in greater detail herein.
Another feature in each of the disclosed embodiments relates to the provision for a gripping area at the lower end of the lower portion of the peripheral side wall, particularly designed to facilitate the extension of the container from the collapsed position.
It is still another feature of the invention to provide various alternative cap engaging portions at the upper end of the container, and to vary the configuration of the upper side wall portion of the container in a manner which rigidifies the upper portion and which also facilitates movement of the container side wall between collapsed and extended positions. It will be understood that the gripping area and cap engaging portion can be reversed, depending on the particular application.
In a first principal embodiment, the upper side wall portion of the container has a substantially uniform diameter in combination with a relatively rigid (but still flexible) annular rim. The rim itself may have the same or greater thickness dimensions than the upper and lower side wall portions.
In one version of this first embodiment, the rim is formed by a radially outwardly extending shoulder which is joined to the upper edge of the upper peripheral side wall portion. The shoulder, in turn, joins with a substantially inverted L-shaped rim comprising a substantially vertical portion and a radially outwardly directed flange terminating at a free edge. This relatively rigid rim also serves as an attachment point for a snap-on type container cap, and its relative rigidity assists in cap retention despite any flexing of the peripheral side wall portions resulting from, for example, accidental dropping of the container, severe squeezing, etc.
In a modified version of this first principal embodiment, the radially outwardly directed flange portion of the rim is omitted so that a screw thread type cap can be utilized.
In another modified version of this, first principal embodiment, the screw thread type connection is replaced by a sliding friction fit.
In each of the above described versions of the first principal embodiment, the cap receiving rim lies outside the diameter of at least the upper and intermediate side wall portions, thus providing a convenient gripping point for the user when extending or collapsing the container.
In still another modified version of this first principal embodiment of the invention, the rim is formed by a radially inwardly inclined shoulder which is joined to an upright annular rim provided with external screw threads for receiving a removable lid. This configuration allows the cap skirt to lie substantially flush with the upper side wall portion of the container when the cap is in place on the container.
In still another version of the first principal embodiment, the upper side wall portion is extended vertically upwardly to the free edge of the side wall, with screw threads provided thereon for receiving the cap. Here, the cap skirt will, of course, lie outside the diameter of the upper side wall portion.
In a second principal embodiment of the invention, the upper side wall portion includes a relatively large radially outwardly extending, hollow annular rib located at the base of the cap receiving rim. The substantially vertical annular cap receiving rim is provided with screw threads for cooperative engagement with mating threads on the interior of the cap skirt. In this second principal embodiment, the cap skirt lies slightly radially inwardly of the outer diameter of the hollow rib when the cap is in place on the container. The radially outwardly projecting hollow rib provides stiffness to the upper end of the container and provides a good gripping point for the user when collapsing or extending the container.
In a third principal embodiment, the upper side wall portion tapers upwardly and outwardly from the intermediate side wall portion, and then upwardly and inwardly to a substantially vertical annular rim provided with screw threads for receiving a cap. When the cap is threadably secured to the container, the cap skirt lies substantially flush with the radially outwardmost surface of the upper peripheral side wall portion of the container.
In all of the embodiments described above, the lower peripheral side wall portion may be telescoped upwardly into the upper peripheral side wall portion, with the intermediate side wall portion reverse folded therebetween. Moreover, in each case, and as noted above, the relative diameters of the upper, intermediate and lower side wall portions are selected to provide adequate axial and radial space to accommodate the telescoping action without excessive friction which would otherwise tend to inhibit the movement between extended and collapsed positions, and vice versa.
It is yet another feature of this invention to provide caps for the container which, as noted above, may be of the snap-on type, screw thread type, or friction fit type. In each case, the cap is provided with an internal skirt which serves to engage and reinforce the annular container rim to provide further insurance of cap retention.
Accordingly, in its broader aspects, the invention relates to a reusable collapsible container comprising a bottom wall and a relatively flexible, peripheral side wall extending upwardly from the bottom wall, the side wall movable between axially extended and collapsed positions and, in the extended position, having lower and upper relatively thicker side wall portions and an intermediate relatively thinner side wall portion, the upper side wall portion formed with an annular rim defining an upper open end of the container, the rim formed with means for receiving a removable cap; and wherein the intermediate side wall portion is tapered downwardly radially inwardly, and the lower side wall portion is tapered downwardly radially outwardly substantially to the bottom wall, such that in the collapsed position, the lower side wall portion is partially telescoped within the upper side wall portion with the intermediate portion reverse folded therebetween, and with an uppermost edge of the lower side wall portion radially spaced away from the upper side wall portion.
In another aspect, the invention relates to a reusable, collapsed container comprising a bottom wall and a peripheral side wall movable between extended and collapsed positions, the side wall in the extended position having upper, lower and intermediate portions, and wherein in the collapsed position, the lower side wall portion is partially telescoped into the upper side wall portion, with the intermediate side wall portion reverse folded therebetween, and wherein the lower side wall portion and the intermediate side wall portion are radially inwardly spaced away from the upper side wall portion.
In still another aspect, the invention relates to a container and cap assembly comprising a container body having a bottom wall and a peripheral side wall extending upwardly from the bottom wall and terminating at an open upper end; the peripheral side wall having upper, intermediate and lower portions, the intermediate portion having a wall thickness substantially less than wall thicknesses of the upper and lower portions; the intermediate portion tapering inwardly in a downward direction and the lower portion tapering outwardly in the downward direction; the upper portion having an annular rim surrounding the open upper end, the annular rim including first means for receiving a removable cap; and a cap having a top wall and a depending skirt, the depending skirt including radially inner and outer rings, the outer ring having second means for cooperating with the first means, and the inner ring engaging an inner surface of the annular rim.
In still another aspect, the invention relates to a reusable collapsible container comprising a bottom wall and a relatively flexible, peripheral side wall extending upwardly from the bottom wall, the side wall movable between axially extended and collapsed positions and, in the extended position, having lower and upper relatively thicker side wall portions and an intermediate relatively thinner side wall portion, the upper side wall portion formed with an annular rim defining an upper open end of the container, the rim formed with means for receiving a removable cap; and wherein the intermediate side wall portion is tapered downwardly radially inwardly, and the lower side wall portion is tapered downwardly radially outwardly substantially to the bottom wall, such that in the collapsed position, the lower side wall portion is partially telescoped within the upper side wall portion with the intermediate portion reverse folded therebetween, and with an uppermost edge of the lower side wall portion radially spaced away from the upper side wall portion, and wherein the radial spacing is determined as a function of the thickness of the upper side wall portion.
The present invention thus provides unique container and cap constructions which are useful for a variety of purposes. It will be appreciated that the container may be advantageously shipped, stocked, and stored between use in the collapsed condition, thus enabling efficient use of space. At the same time, the container is easily expandable to an enlarged volume, and is particularly well suited for the storage of foodstuffs (frozen or refrigerated) or other material.